Nectarine tree, &#39;burnectwentyone&#39;

ABSTRACT

A new and distinct variety of nectarine tree ( Prunus nucipersica ), and which is denominated varietally as ‘Burnectwentyone’, and which produces an attractively colored yellow-fleshed, clingstone, nectarine which is mature for harvesting approximately September 21 to October 2 under the ecological conditions prevailing in the San Joaquin Valley of central California.

BACKGROUND OF THE NEW VARIETY

The present invention relates to a new, novel and distinct variety of nectarine tree, ‘Prunus nucipersica,’ and which has been denominated varietally as ‘Burnectwentyone’ hereinafter.

The present variety of nectarine tree resulted from an on-going program of fruit and nut tree breeding. The purpose of this program is to improve the commercial quality of deciduous fruit and nut varieties, and rootstocks, by creating and releasing promising selections of prunus, malus and regia species. To this end we make both controlled and hybrid cross pollinations each year in order to produce seedling populations from which improved progenies are evaluated and selected.

The seedling, ‘Burnectwentyone’, was originated by us from a population of seedlings grown in our experimental orchards located near Fowler, Calif. The seedlings, grown on their own roots, were the result of planting seeds which were derived from the open pollination of the ‘Burnectfour’ nectarine tree (U.S. Pat. No. 13,477). ‘Burnectfour’ resulted from a previous cross of the yellow-fleshed clingstone nectarine tree ‘September Red’ (U.S. Pat. No. 5,664), which was used as the seed parent; and the ‘Spring Bright’ nectarine tree (U.S. Plant Pat. No. 7,507) which was used as the pollen parent. The open pollination of the ‘Burnectfour’ nectarine tree occurred sometime in March 1998. Thereafter seeds derived from this open pollinated seedling tree were planted in September of 1998. One subsequent seedling, denoted as I 10.067, which is the present variety, exhibited especially desirable characteristics, and was marked for subsequent observation. After the 2000 fruiting season, the new variety of nectarine tree was selected for advanced evaluation and repropagation.

ASEXUAL REPRODUCTION

Asexual reproduction of this new and distinct variety of nectarine tree was accomplished by budding the new nectarine tree onto ‘Nemaguard’ Rootstock (non-patented). This was performed by us in our experimental orchard located near Fowler, Calif. Subsequent evaluations have shown those asexual reproductions run true to the original tree. All characteristics of the original tree, and its fruit, were established and appear to be transmitted through succeeding asexual propagations.

SUMMARY OF THE VARIETY

‘Burnectwentyone’ is a new and distinct variety of nectarine tree, which is considered of large size, and which has vigorous growth. This new nectarine tree is also a regular and productive bearer of relatively large, firm, yellow fleshed, acidic clingstone fruit which have good flavor and eating qualities. This new tree has a medium chilling requirement of approximately 700 hours, and further produces relatively uniformly sized fruit throughout the tree. In addition, the fruit also appears to have good handling and shipping qualities. Still further, the ‘Burnectwentyone’ nectarine tree bears fruit which are ripe for commercial harvesting and shipment on approximately September 23 to October 2 under the ecological conditions prevailing in the San Joaquin Valley of central California. In relative comparison to the seed parent, ‘Burnectfour’, the present nectarine tree bears fruit about 18 or more days earlier at the same geographical location. In relative comparison to other known varieties, the present variety of nectarine tree is most closely similar to the ‘September Red’ Nectarine (U.S. Plant Pat. No. 5,662), which, when grown in its natural state, produces fruit that ripens on or about September 1st, whereas the present new variety produces fruit which has a ripening date of September 23 or later. Further in comparison to the “Spring Bright’ nectarine tree, the present variety ripens typically after September 23, whereas the ‘Spring Bright’ nectarine tree produces fruit which are ripe for harvesting between June 21-June 29 at Le Grand, Calif.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing, is a color photograph of the present variety. This photograph depicts two whole mature fruit, and one fruit dissected substantially in the equatorial plane exposing the fruit flesh. The exposed flesh and skin exhibits fruit sufficiently matured for harvesting ands shipment. Additionally, the photograph displays a sample vegetative shoot bearing typical leaves, and a stone, with the flesh removed. The colors in this photograph are as nearly true as is reasonably possible in a color representation of this type. Due to chemical development, processing and printing, the leaves and fruit depicted in these photographs may or may not be accurate when compared to the actual specimen. For this reason, future color references should be made to the color plates (Royal Horticultural Society) and other more general color descriptions provided hereinafter.

DETAILED DESCRIPTION

Referring more specifically to the pomological details of this new and distinct variety of nectarine tree, the following has been observed during the fourth fruiting season under the ecological conditions prevailing at orchards which are located near the town of Fowler, county of Fresno, state of Calif. All major color code designations are by reference to the RHS Colour Chart (Fourth Edition) and which is provided by The Royal Horticultural Society of Great Britain. Common color names are also occasionally used.

-   Tree:     -   -   Size.—Generally. — Considered medium-large as compared to             other common commercial nectarine cultivars ripening in the             late season of maturity. The tree of the present variety was             pruned to a height of approximately 305.0 cm to about 315.0             cm at maturity.         -   Vigor.—Considered moderately vigorous. The present nectarine             tree variety grew from about 135.0 cm to about 140.0 cm in             height during the first growing season. The new variety was             pruned to a height of approximately 125.0 cm during the             first dormant season, and primary scaffolds were then             selected for the desired tree structure.         -   Productivity.—Productive. Fruit set varies from about 1.5 to             several times more than the desired crop load. Fruit set is             spaced by thinning to develop the remaining fruit into the             desired market sized fruit. The number of the fruit set             varies with the prevailing climatic conditions, and cultural             practices employed, and is therefore not distinctive of the             present variety.         -   Bearer.—Regular. Fruit set has been heavy during the years             of observation, and thinning was necessary during the past 5             years.         -   Form.—Upright, and pruned to a vase shape.         -   Density.—Considered medium dense. It has been discovered             that pruning the branches from the center of the tree to             obtain a resulting vase shape allows for air movement and             appropriate amounts of sunlight to enhance fruit color, and             renewal of fruiting wood throughout the tree.         -   Hardiness.—The present tree was grown and evaluated in USDA             Hardiness Zone 9. Winter chilling requirements of the new             tree are approximately 700 hours below 7.0 degrees C. The             variety appears to be hardy under typical central San             Joaquin Valley climatic conditions. -   Trunk:     -   -   Diameter.—Approximately 13.0 cm in diameter when measured at             a distance of approximately 15.24 cm above the soil level.             This measurement was taken at the end of the fifth growing             season.         -   Bark texture.—Considered moderately rough, with numerous             folds of papery scarfskin being present.         -   Lenticels.—Numerous flat, oval lenticels are present. The             lenticels are relatively large, and range in size from             approximately 5.0 to about 6.0 millimeters in width, and             from 1.0 to about 2.0 millimeters in height.         -   Lenticel color.—Considered an orange brown, (RHS             Greyed-Orange Group N170 A).         -   Bark coloration.—Variable, but it is generally considered to             be a medium grey-brown, (RHS Greyed-Orange Group 174 A). -   Branches:     -   -   Size.—Considered medium for the variety.         -   Diameter.—Average as compared to other nectarine varieties.             The branches have a diameter of about 6.2 centimeters when             measured during the third year after grafting.         -   Surface texture.—Average, and appearing furrowed on wood             which is several years old.         -   Crotch angles.—Primary branches are considered variable, and             are between about 45 to 50 degrees when measured from the             horizontal axis. This particular characteristic is not             considered distinctive of the variety, however.         -   Current season shoots.—Surface texture — Substantially             glabrous.         -   Internode length.—Approximately 2.3 to about 2.5 cm.         -   Color of mature branches.—Medium brown, (RHS Greyed-Orange             177 B).         -   Current season shoots.—Color. — Green, (RHS Green Group 137             A). The color of new shoot tips is considered a bright and             shiny green (RHS Green Group 143 B). -   Leaves:     -   -   Size.—Considered medium for the species. Leaf measurements             have been taken from vigorous, upright, current-season             growth at approximately mid-shoot.         -   Leaf length.—Approximately 143.0 to about 155.0 millimeters.         -   Leaf width.—Approximately 35.0 to about 39.0 millimeters.         -   Leaf base shape.—Slightly oblique relative to the leaf             longitudinal axis.         -   Leaf form.—Lancelolate.         -   Leaf tip form.—Acuminate.         -   Leaf color.—Upper Leaf Surface — Dark green, (approximately             RHS Green Group 139 A).         -   Leaf texture.—Glabrous.         -   Leaf color.—Lower Surface — Medium green, (RHS Yellow-Green             Group 147 A).         -   Leaf venation.—Pinnately veined.         -   Mid-Vein.—Color. — Light yellow green, (RHS Greyed-Yellow             Group 160 B).         -   Leaf margins.—Slightly undulating.         -   Form.—Considered crenate.         -   Uniformity.—Considered generally uniform. -   Leaf petioles.—Size. — Considered medium-long. Length. — About 8.0     to about 11.0 mm. Diameter. — About 1.5 to about 2.0 mm. Color. —     Pale green, (RHS Yellow-Green Group N144 A). -   Leaf glands.—Size. — Considered small. Approximately 1.5 mm in     length, and about 1.0 mm in height. Number. — Generally one gland     per margin side. Occasionally two glands per margin side may be     found. Type. — Reniform. Color. — Considered a pale orange (RHS     Orange Group 26 B).     -   -   Leaf stipules.—Size. — Medium for the variety. Number. —             Typically 2 per leaf bud, and up to 6 per shoot tip. Form. —             Lanceolate in form and having a serrated margin. Color. —             Green, (RHS Yellow-Green Group 144 A) when young, but             graduating to a brown color, (RHS Greyed-Orange group 165 B)             with advancing senescence. The stipules are considered to be             early deciduous. -   Flowers:     -   -   Flower buds.—Generally — The floral buds, depending upon the             stage of development, are approximately 7.5 millimeters             wide; about 11.0 millimeters long; conic in form; and             slightly appressed relative to the bearing shoot. Floral bud             dimensions are highly dependant upon the timing of the             measurements.         -   Flower buds.—Color — This characteristic is dependent upon             the proximity to the bloom. The bud scales are purple,             (approximately RHS Greyed-Purple Group N186C). The buds are             considered hardy under typical central San Joaquin Valley             climatic conditions.         -   Hardiness.—No winter injury has been noted during the last             several years of evaluation in the central San Joaquin             Valley. The current variety has not been intentionally             subjected to drought or heat stress, and therefore this             information is not available.         -   Date of first bloom.—Mar. 1, 2004.         -   Blooming time.—Considered mid-season in relative comparison             to other commercial nectarine cultivars grown in the central             San Joaquin Valley. The date of full bloom was observed on             Mar. 7, 2004. The date of bloom varies slightly with             climatic conditions and cultural practices.         -   Duration of bloom.—Approximately 9 days. This characteristic             varies slightly with the prevailing climatic conditions.         -   Flower type.—The variety is considered to have a showy type             flower.         -   Flower size.—Flower diameter at full bloom is approximately             41.0 to about 44.0 millimeters.         -   Bloom quantity.—Considered abundant.         -   Flower bud frequency.—Normally 1 or more flower buds appear             per node.         -   Petal size.—Generally — Considered medium-large for the             species. Length. — Approximately 18.0 to about 21.0             millimeters. Width. — Approximately 18.0 to about 20.0             millimeters.         -   Petal form.—Generally rounded.         -   Petal count.—Nearly always 5.         -   Petal texture.—Glabrous. Petal Color. — Light pink,             approximately (RHS Red-Purple Group 65 D).         -   Fragrance.—Slight.         -   Petal claw.—Form. — The claw is generally elongated, and has             a medium size when compared to other varieties. Length. —             Approximately 9.0 to about 12.0 millimeters. Width. —             Approximately 9.0 to about 10.0 millimeters. Petal Margins.             — Generally considered reasonably uniform and smooth, and             moderately undulate.         -   Petal apex.—Generally — The petal apices exhibit a small             narrow groove at the tip.         -   Flower pedicel.—Length. — Considered medium-long, and having             an average length of approximately 3.0 to about 5.0             millimeters. Diameter. — Considered average, approximately             3.0 millimeters. Color. — A dull green, (RHS Yellow-Green             Group 144 C).         -   Floral nectaries.—Color. — A dull orange, (RHS Greyed-Orange             Group N172 B).         -   Calyx.—Surface Texture. — Generally glabrous. Color. —             Purple, (approximately RHS Greyed-Red Group 180 B).         -   Sepals.—Surface texture. — The surface has a short, fine             pubescent texture. Size. — Average, and ovate in form.             Color. — A deep purple, (approximately RHS Greyed-Purple             Group 183 A).         -   Anthers.—Generally. — Average in length. Color. — Red to             reddish-orange dorsally, (approximately RHS Greyed-Red Group             179 A). Pollen Production. — Pollen is abundant, and has a             yellow color, (approximately RHS Yellow-Orange Group 17 C).             The present variety is considered self-fruitful, and does             not require a pollinator.         -   Filaments.—Size. — Length is variable, approximately 15.0 to             about 18.0 millimeters long. Color. — Considered light pink,             (RHS Red Group 36 D).         -   Pistil.—Number. — Usually 1, rarely 2. Generally. —             Medium-long in size. Length. — Approximately 18.0 to about             21.0 millimeters including the ovary. Color. — Considered a             very pale green, (approximately RHS Yellow-Green Group 145             C). Surface Texture. — The variety has a long glabrous             pistil. -   Fruit:     -   -   Maturity when described.—Firm ripe condition (shipping             ripe). Date of first picking. — Sep. 21, 2004. Date of last             picking. — Oct. 2, 2004. The date of harvest varies slightly             with the prevailing climatic conditions and fruit maturity             harvested for preferred market requirements.         -   Size.—Generally — Considered large, and uniform.         -   Average cheek diameter. — Approximately 72.0 to about 75.0             millimeters.         -   Average axial diameter. — Approximately 69.0 to about 71.0             millimeters.         -   Typical weight.—Approximately 285.0 grams. This             characteristic is highly dependent upon the prevailing             cultural practices, and therefore is not particularly             distinctive of the variety.         -   Fruit form.—Generally rounded. The fruit is generally             uniform in symmetry.         -   Fruit suture.—A shallow suture indentation is evident from             the stem well, throughout the length of the fruit, and             slightly past the apex. No apparent callousing or stitching             exists along the suture line.         -   Suture.—Color — This has a yellow background color,             (approximately RHS Yellow-Orange Group 20 D).         -   Ventral surface.—Form — Slightly indented.         -   Apex.—Rounded.         -   Base.—Generally retuse.         -   Stem cavity.—Generally uniform and rounded in shape and             moderately deep. Average depth of the stem cavity is about             7.0 mm. Average width of the stem cavity is about 15.0 mm.         -   Fruit skin.—Thickness. — Considered medium in thickness, and             tenacious to the flesh. Texture. — Glabrous. Taste. —             Non-astringent. Tendency to crack. — None observed.         -   Color.—Blush Color. — This blush color is generally red             (approximately RHS Orange-Red Group N34 A). The blush covers             approximately 50-60% of the fruit skin surface. The             percentage of the blush on the fruit skin surface can vary,             and is generally dependant upon the prevailing conditions             under which the fruit was grown. Ground Color. — Yellow             orange, (approximately RHS Yellow-Orange Group 22 B).         -   Fruit stem.—Medium, approximately 5.0 to about 7.0             millimeters. Diameter. — Approximately 2.0 to 3.0             millimeters. Color. — Pale yellow-green, (approximately RHS             Yellow-Green Group 144 A).         -   Flesh.—Ripens. — Evenly. Texture. — Firm, juicy and dense.             The flesh is considered non-melting. Fibers. — Few, small,             and tender ones are typically found. Aroma. — Very slight.             Eating Quality. — Considered very good. Flavor. — Considered             sweet and slightly acidic. The flavor is considered both             pleasant and balanced. Juice. — Moderate. Brix. — About 15.5             degrees. This characteristic varies slightly with the number             of fruit per tree; prevailing cultural practices; and the             surrounding climatic conditions.         -   Flesh color.—Pale yellow-orange, (approximately RHS             Yellow-Orange Group 18 B). -   Stone:     -   -   Type.—Clingstone.         -   Size.—Considered medium for the variety. The stone size             varies significantly depending upon the tree vigor, crop             load and prevailing growing conditions.         -   Length.—Average, about 29.0 to about 32.0 millimeters.         -   Width.—Average, about 26.0 to about 28.0 millimeters.         -   Diameter.—Average, about 16.0 to about 18.0 millimeters.         -   Form.—Generally rounded.         -   Base.—The stone is usually oblique toward the ventral side.         -   Apex.—Shape. — Generally the stone apex has a small rounded             tip.         -   Stone surface.—Surface Texture — Pitting, in general is             prominent in the mid-section and toward the base. Ridges. —             The surface texture is generally characterized by more             prominent ridges along the ventral and dorsal margins.             Ventral Edge. — Width — Considered medium, and having a             dimension of approximately 3.0 to about 4.0 millimeters when             measured at the mid-suture. Dorsal Edge. — Shape. — Oblique             toward the stem end.         -   Stone color.—The color of the dry stone is generally             considered a reddish brown, (approximately Greyed-Orange             Group RHS N170 C).         -   Tendency to split. — Splitting has rarely been noted.         -   Kernel.—Size. — The kernel is considered medium. Form. —             Considered generally ovoid. Pellicle. — Pubescent and             ridging is usually absent. Color. — (RHS Greyed-range Group             N167 B).         -   Use.—The subject variety ‘Burnectwentyone’ is considered to             be a nectarine tree of the late season of maturity, and             which produces fruit that are considered firm, attractively             colored, and which are useful for both local and long             distance shipping.         -   Keeping quality.—Excellent. Fruit has stored well for up to             25 days after harvest at 1.0 degree Celsius.         -   Shipping quality.—Considered good. The fruit of the new             nectarine variety showed minimal bruising of the flesh or             skin damage after being subjected to normal harvesting and             packing procedures.         -   Resistance to insects and disease.—No particular             susceptibilities were noted. The present variety has not             been tested to expose or detect any susceptibilities or             resistances to any known plant and/or fruit diseases.

Although the new variety of nectarine tree possesses the described characteristics when grown under the ecological conditions prevailing near Fowler, Calif., in the central part of the San Joaquin Valley of California, it should be understood that variations of the usual magnitude and characteristics incident to changes in growing conditions, fertilization, pruning, pest control and horticultural management are to be expected. 

1. A new distinct variety of nectarine tree substantially as illustrated and described, and which is characterized principally as to novelty by producing an attractively colored yellow-fleshed, clingstone, nectarine which is mature for harvesting approximately September 21 to October 2 under the ecological conditions prevailing in the San Joaquin Valley of central California. 